<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>vw和vh</title>
    <style>
        /* *{margin: 0;padding:0;box-sizing: border-box}
        #banner{
            width: 92vw;
            height: 40vw;
            margin: 20vw auto;
            background: #569;
        } */
    </style>
    <link rel="stylesheet" href="./index.css">
</head>
<body>
    <div id="banner"></div>
</body>
</html>